Bridged dihydroxynaphthalene and bridged dihydroxyanthracene silver halide developing agents and antifoggants



United States Patent 3,459,549 BRIDGET) IDTHYDROXYNAPHTHALENE AND BRIDGED DTHYDROXYANTHRACENE SIL- VER HALHDE DEVELOPING AGENTS AND ANTIFUGGANTS Clarence E. McBride, David F. OBrien, and John W.

Gates, Jr., Rochester, N.Y., assignors to Eastman Kogak Company, Rochester, N. Y., a corporation of New ersey No Drawing. Continuation-impart of application Ser. No. 454,700, May 10, 1965. This application July 13, 1967, Ser. No. 653,031

Int. Cl. G03c 5/30 U.S. Cl. 96-665 22 Claims ABSTRACT OF THE DISCLOSURE Photographic developing agents and antifoggants comprising bridged l,4- and 1,Z-dihydroxynaphthalenes and bridged 9,lO-d'ihydroxyanthracenes.

This is a continuation-in-part application of U.S. Ser. No. 454,700, filed May 10, 1965, now abandoned, in the names of Clarence E. McBride, David F. OBrien and John W. Gates, Jr.

This invention relates to silver halide developing agents and antifoggants. In one of its aspects, the invention is directed to bridged polyhydroxynaphthalenes and bridged dihydroxyanthracenes as silver halide developing agents in developer compositions and/or incorporated in photographic elements.

It is known to employ silver halide developing agents in processing silver halide emulsions. It is also known to incorporate silver halide developing agents in photographic silver halide emulsion layers. Such emulsions are developed after light exposure, by treating them in alkaline solutions which may or may not contain a developing agent. Following development by either system, the developed silver image can be fixed, for example, by treating the developed silver halide layer in a conventional sodium thiosulfate fixing bath. The developed and fixed photographic emulsion layer can then be washed and dried.

In many processes of the kind mentioned in the foregoing, it has been proposed to incorporate a tanning silver halide developing agent directly in a sensitive emulsion. Although this is convenient, it is frequently disadvantageous because the concentration of developing agent in the coating is gradually reduced on storage for one or more reasons, e.g. diffusion, sublimation, oxidation, or the like. Thus, the developing agent may gradually become oxidized sufficiently to tan the gelatin so that the material deteriorates on storage and may become ineffective after some keeping.

It is also Well known in the photographic art to employ developing agents, the oxidation products of which react with gelatin to raise its melting point, harden or tan it so as to modify its physical properties. The layer can then be subjected to warm water to remove the untanned gelatin and the under-developed or background areas, leaving a gelatin relief containing a silver image. This gelatin relief by virtue of the density provided by the silver image comprises a useable photographic image.

'ice

The difference in absorption between the gelatin relief areas and the background can be used for imbibition of dye solutions for transfer to mordanted receiving sheets. The relief can also be used in photomechanical processes, such as typography or gravure. The difference in inkwater receptivity of the gelatin relief and the hydrophobic support can be employed in lithographic printing or the relief can be transferred to other supports, such as silk screen for stencil printing and the like. Alternatively, the difference in the ink receptivity of the reacted and unreacted areas can be employed directly without washoif as in the lithographic printing process of U.S. Patent 3,146,104, issued Aug. 25, 1964, to Yackel and Abbott.

In the usual process of photographic development, the exposed photographic element comprising a support having at least one gelatin silver-halide emulsion layer thereon, is immersed in a developing bath containing a silver halide photographic developing agent. The developing bath is normally maintained as a separate processing bath and with continuous use, the bath usually becomes less efficient so that special techniques and replenishments are required to maintain optimum processing efficiency. The developing baths of the prior art normally contain a developing agent, a preservative, such as sodium sulfite, alkali to activate the developing agent, and can also contain other materials, such as sodium bromide as a restrainer, antifoggants, etc.

Certain of the tanning developing agents suitable for use as incorporated developers are disclosed in U.S. Patent 2,592,368. These compounds are broadly identified as dihydroxydiphenyl tanning developing agents, and are particularly useful in processes where a high degree of tanning is desired. However, in certain situations, the degree of tanning must be such as to permit ready removal of the unhardened areas such as by washing with warm water, but must be such as to permit stripping of the tanned or hardened areas from the support. A suitable developing agent should preferably be water soluble. Accordingly, it has been desirable to find a water soluble tanning agent which would have a satisfactory degree of tanning for certain processes such as for use in gravure printing processes and which would also have satisfactory stability when incorporated in a silver halide emulsion.

It is also desirable to add components to the emulsion which have antifogging properties. These compounds are added in addition to the other addenda which are present in the emulsion and have the effect of reducing the fog which would be present in the emulsion as a result of conventional development.

Thus, one object of this invention is to provide novel silver halide developing agents. Another object is to provide silver halide emulsions having incorporated therein improved developing agents. A further object is to provide silver halide emulsions having incorporated therein improved tanning developing agents which are photographically compatible and which are stable to atmospheric oxygen. Another object is to provide silver halide photographic materials having an incorporated tanning developer suitable for use in a stripping product such as that used for preparing gravure printing plates. A further object is to provide a tanning developing agent which provides a degree of hardness in the tanned silver halide emulsion, which permits it to be stripped from a temporary support.

A still further object is to provide an antifoggant for use in developing solutions and for incorporation in photographic emulsions, which has improved antifoggant properties over prior art antifoggants.

The silver halide developing agents of the invention comprise bridged dihydro-l,4-dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-1,Z-dihydroxynaphthalenes, bridged tetrahydro-l, Z-dihydroxynaphthalenes, bridged tetrahydro-9,10-dihydroxyanthracenes, bridged hexahydro-9,IO-dihydroxyanthracenes and bridged octahydro-9,lo-dihydroxyanthracenes within the following general formulas:

R6\7 8 Rx 6 X R; R2

III

OH R

12 wherein R R and R are each hydrogen; alkyl, for example, alkyl containing 1 to about 20 carbon atoms, such as ethyl, propyl, amyl, decyl and tridecyl; aryl, for example, phenyl, tolyl, or xylyl; hydroxy; alkoxy, e.g. lower alkoxy, such as methoxy, ethoxy or propoxy; a sulfonic acid group; halogen; amino, such as NH NHZ, or NZ in which Z is a lower alkyl group; or a thio group, such as SY wherein Y represents hydrogen or an isocyclic group, for example, an aryl group such as phenyl, naphthyl, tolyl, xylyl or a heterocyclic group, for example, a tetrazolyl, a thiazolyl or a quinolinyl group; at least one of R R or R being hydroxy, R R R R R8, R9, R10, R11, R12, R13, R14 and R15 each are hydrogen, aryl, for example, phenyl, tolyl, xylyl, and the like, or

lower alkyl, for example, methyl, ethyl, propyl, butyl or amyl; wherein x and y, which can be either the same or different, each represents on each of the number 5 and 8 carbon atoms in Formulae I and II, and on each of the number 1, 4, 5 and 8 carbon atoms in Formulae III, IV, and V, an oxygen atom, or a methylene or ethylene group, which groups may be optionally substituted with a halogen atom, an aryl group, for example, those enumerated above, or a. lower alkyl group, for example, methyl, ethyl, propyl, butyl or amyl. Compounds of this type have been described by O. Diels and K. Alder, Bericht, 62, 2337 (1929) and by Porter et al., J. Org. Chem., 29, 588 (1964).

Particularly suitable groups or classes of compounds within the scope of the above structures I and II are: 5,8-rnethano-5,8-dihydro 1,4 dihydroxynaphthalenes of the formula:

5,8-ethano-5,8-dihydro-l,2-dihydroxynaphthalenes of the formula:

VII

5,8-methano-5,6,7,8-tetrahydro 1,2 dihydroxynaphthalenes of the formula:

VIII

5,8-ethano-5,6,7,S-tetrahydro-1,2 dihydroxynaphthalenes of the formula:

R 5,8-methano-5,8-dihydro 1,4 dihydroxynaphthalenes of the formula:

and 5,8-ethano-5,8-dihydro-l,4-dihydroxynaphthalenes of the formula:

XIII

wherein in each of structures VI, VII, VIII, IX, X, XI, XII and XIII R is hydrogen; aryl, such as phenyl, tolyl and xylyl; alkyl, such as those containing 1 to about 20 carbon atoms, including methyl, ethyl, propyl, butyl, t-butyl, and octyl, especially lower alkyl; hydroxy; alkoxy, especially lower alkoxy such as methoxy, ethoxy, or propoxy; sulfonic acid; halogen, especially chlorine, bromine, or iodine; amino, including NH NHZ and NZ wherein Z is lower alkyl; or thio, such as SY wherein Y is as defined above, including, for example, tetrazolyl, etc.,

One embodiment of the invention is a photographic element comprising a support having a hydrophilic colloid layer containing a compound of the class consisting of bridged dihydro-1,4-dihydroxynaphthalenes, bridged tetrahydro-l,4-dihydroxy-naphthalenes, bridged tetrahydro-l, Z-dihydroxynaphthalenes, bridged tetrahydro-9,lO-dihydroxyanthracenes, bridged hexahydro-9,10-dihydroxyanthracenes, and bridged octahydro-9,l-dihydroxyanthra cenes. The hydrophilic colloid layer can be a photographic silver halide emulsion layer on a support, or it can be a layer contiguous to a silver halide emulsion layer. The element also can be a multilayer photographic element comprising a support having thereon at least one photographic layer sensitive to the blue region of the spectrum, at least one photographic layer sensitive to the green region of the spectrum and at least one photographic layer sensitive to the red region of the spectrum, containing in at least one layer of said element a compound of the class consisting of bridged dihydro-lA'dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-1,2-dihydroxynaphthalenes, bridged tetrahydro-l,2-dihydroxy-naphthalenes, bridged tetrahydro-9,IO-dihydroxyanthracenes, bridged hexahydro-9,10- dihydroxyanthracenes, and bridged octahydro-9,10-dihydroxyanthracenes containing in at least one layer at least one of the above compounds.

An example of a particularly useful compound within the scope of structure I and XII is 5.8-methano-5,6,7,8-

tetrahydro-l,4-dihydroxynaphthalene, also known as 3,6- dihydroxybenzouorboruane, of the formula:

When used as an incorporated developing agent, it can be incorporated in a hydrophilic colloid, such as a silver chlorobromide gelatin emulsion, which is then coated on a suitable support, e.g., over a stripping layer on a temporary film support. This material can be exposed and then processed in an alkaline solution after which the emulsion is transferred to a copper cylinder for use as etching resist to obtain a gravure printing plate.

In one embodiment of the invention, dihydro or tetrahydro bridged 1,4-dihydroxynaphthalene developing agent, such as those within the scope of structure XII, is dissolved in water and the pH of the aqueous solution raised to about 10 by the addition of alkali e.g., sodium hydroxide, after which an exposed silver halide emulsion is developed by immersing or otherwise contacting the exposed meulsion with the solution for a sufficient time to produce the desired density.

It has also been found that substitution in one of the positions of the above compounds adjacent to the hydroxy groups results in developers which do not tan. Compounds of this structure are described by Meinwald and Wiley, JACS 80, 3667 (1958) and by Porter et al, J. Org. Chem, 29 588 (1964). Particularly useful bridged dihydro and tetrahydro-1,4-dihydroxy compounds are those who do not have any continuents on the rings. However, the bridge can have substitutents thereon referred to above, e.g., a methylene or ethylene bridge in the 5,8- position of structures I or II can be substituted with various groups described hereinbefore, especially lower alkyl groups.

It will be appreciated that these developing agents can be used as mixtures and particularly as mixtures of tanning developing and non-tanning developing agents where desirable. They may also be used as mixtures with other developers known in the art and can be used in any suitable forrn for developing an exposed photographic element. For instance, they can be used in an aqueous silver halide developer solution or liquid concentrate, as a component of a solid particulate developer composition suitable for dissolving in an aqueous solvent, as a viscous developer composition containing various thickening agents, as a packaged component of a kit for mixing with various photographic processing agents or as a component of a fusible solid such as a solid comprising a homogeneous mixture of an alkylene oxide polymer and a developing agent of the invention which melts above about room temperature, and the like.

When the compounds of this invention are used as antifoggants, they can be incorporated in a conventional developing solution or incorporated in the silver halide photographic emulsion. If desired, they may be used both both in the developing solution and in the emulsion and various combinations of species Within the generic class of these compounds may be used, such as mixtures or a combination of different species with respect to the incor porated antifoggant and the antifoggant in the developing solution.

In one embodiment for use as an antifoggant, a silver halide emulsion, such as a medium-grained silver bromoiodide gelation emulsion is prepared and a bridged dihydroxy compound of this invention, such as 3,6-dihydroxy benzonorbornane is added to the emulsion in an amount which may usefully be about 6.0 g./rnole of silver halide present in the photographic emulsion. However, when compounds of the invention are used as antifoggants, concentrations of 1.2 to 6.0 g./mole of silver halide can be used although the amount can be varied depending upon the particular compounds, and the presence of other components including other antifoggants and developers. In some instances, a species can be employed as an antifoggant, whereas a different species can be incorporated as a developing agent. In other instances, the antifoggant can be in the developing solution, such as in an amount of about 100-300 mg./l. However, of course, this may be varied widely depending upon other addenda in the developing solution and in the emulsion.

It will be appreciated that various activator baths can be used with an emulsion containing an incorporated developer of the invention, such as for example, an aqueous solution of an alkaline material, such as sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide, mixtures of sodium hydroxide and sodium sulfite, etc. Suitable ba'ths can comprise, for example, an aqueous solution containing about 1 percent sodium hydroxide and percent sodium sulfite. A bath of the latter type is quite suitable for developing an exposed emulsion layer in about 30 seconds when the activator bath is at about 68 F. Modifications can easily be made in the activator baths Without departing from the spirit and scope of the invention. For example, an aqueous solution comprising about 4 percent sodium carbonate and 5 percent sodium sulfite produces development in about 30 seconds at about 68 F. Another aqueous activator solution comprising 2 percent sodium hydroxide and 5 percent sodium sulfite produces useful photographic images in a few seconds when heated at 130 F. Particularly useful activator solutions have a pH of at least 8.5.

The activator solutions may be applied to an exposed photographic element in any number of known ways, such as, by dipping, spraying, or other suitable surface applications. If desired, a thickener can be added to the activator solution to increase the viscosity of the composition and make it more adaptable for continuous processing. Viscous compositions can then be removed by squeegeeing or water spraying.

The concentration of the developing agents used in our invention will vary depending upon the particular chemical compound involved and the location of the compound Within the puhotographic element. That is, if the developing agent of the invention is incorporated within the silver halide emulsion undergoing development, it may be desirable to use a somewhat different concentration than would be used if the developer were incorporated in a layer contiguous to the photographic silver halide emulsion. The useful concentration of developer .for incorporation in the emulsion is from about 0.01 to about 4.0 moles/mole of silver halide. A particularly useful range is from 0.1 to 2.0 moles/mole of silver halide, with especially useful results being obtained within the range of about 0.4 to 1.0 mole/mole of silver halide. For incorporation in a layer contiguous to the silver halide emulsion layer, somewhat larger concentrations of developer can be tolerated without adverse effects.

Photographic silver halide emulsions useful in our invention comprise any silver halide emulsions ordinarily employed as developing out emulsions, such as silver chloride, silver iodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide, silver bromide and silver bromoiodide developing-out emulsions. Any of the conventionally employed water-permeable hydrophilic colloids can be employed in the silver halide emulsions, or in a layer contiguous thereto. Typical water-permeable hydrophilic colloids include gelatin, albumin, polyvinyl alcohol, agar agar, sodium alginate, hydrolyzed cellulose esters, hydrophilic polyvinyl copolymers, etc.

Other addenda known in the art may be used with the silver halide emulsions of our invention. The silver halide emulsions may be chemically sensitized with compounds of the sulfur group, e.g. sulfur sensitizers, selenium sensitizers, tellurium sensitizers, noble metal salts, such as gold or reduction sensitizers with reducing agents or combinations of such sensitizers. The silver halide emulsions of this invention may contain spectral sensitizers, such as the cyanines, merocyanines, styryls, hemicyanines, speedincreasing compounds such as polyalkylene glycols, onium salts and thioethers, stabilizers such as azaindenes, cadmium and other divalent salts, mercury compounds, azoles and mercaptans, coating aids, such as non-ionic, anionic and amphoteric surface active agents, etc.

The addenda which we have described may be used in various kinds of photographic emulsions. In addition to being useful in X-ray and other non-optically sensitized emulsions, they may also be used in orthochromatic, panchromatic, infrared sensitive emulsions, and lith type emulsions which usually are developed to high contrast in developing solutions having a low concentration of sulfite ions. They may be added to the emulsion before or after any sensitizing dyes which are used.

The agents described herein can be used in emulsions intended for color photography, for example, emulsions containing color-forming couplers or emulsions to be developed by solutions containing couplers or other colorgenerating materials, emulsions of the mixed-packet type, such as described in Godowsky, U.S. Patent 2,698,794, issued Jan. 9, 1955; or emulsions of the mixed-grain type, such as described in Carroll and Hanson, U.S. Patent 2,592,243.

It has been found that the development rate of the developing agents above can be improved by adding an auxiliary developing agent either to the silver halide emulsion layer, or a hydrophilic layer contiguous thereto. Typical auxiliary developing agents include polyhydroxybenzene developing agents, such as hydroquinone, t-butylhydroquinone, chlorohydroquinone, pyrocatechol and the like, p-aminophenols, such as 2,4-diaminophenols, and 3- pyrazolidone compounds containing an alkyl, e.g. methyl or ethyl, or aryl substituent, e.g. phenyl, p-tolyl, etc. In addition, such pyrazolidone developing agents can contain an acyl or acyloxy substituent which can be hydrolyzed from the 3-pyrazolidone compound by treatment with the above activator solutions to produce the desired auxiliary developing compound. Typical auxiliary developing agents include, for example, 1-phenyl-3-pyrazolidone, 1-p-tolyl-3- pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone, l-acetamidophenyl 3 pyrazolidone, 3-acetoxy-1-phenyl-3-pyrazolidone (Enol ester), Z-(pyridinium acetyl)-1-phenyl-3- pyrazolidone chloride, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, l-phenyl-Z-benzoyl-3-pyrazolidone, 1-phenyl-2-lauroy1-3-pyrazolidone, 1- phenyl-2-chloroacetyl-3-pyrazolidone, etc.

The concentration of auxiliary developing agents can be varied and, of course, no auxiliary developing agent need be employed unless so desired. Useful concentrations of auxiliary developing agents vary from about 0.01 mole to 2.0 moles per mole of developing agent. Depending upon the particular auxiliary developing agent employed, larger or smaller quantities can be used.

The developers of the invention can be used in colloid transfer processes and elements such as that set out in U.S. Patent 2,596,752, issued May 13, 1952.

The developing agents of this invention can be used in emulsions intended for use in diffusion transfer processes which utilize the undeveloped silver halide in the nonimage areas of the negative to form a positive by dissolving the undeveloped silver halide and precipitating it on a receiving layer in close proximity to the original silver halide emulsion layer. Such processes are described in Rott U.S. Patent 2,352,014, issued June 20, 1944, and Land U.S. Patents 2,584,029, issued I an. 29, 1952; 2,698,236, issued Dec. 28, 1954, and 2,543,181, issued Feb. 27, 1951; and Yackel et al. U.S. Patent 3,020,155, issued Feb. 6, 1962. They may also be used in color transfer processes which utilize the diffusion transfer of an image-wise distribution of developer, coupler or dye, from a light-sensitive layer to a second layer, while the two layers are in close proximity to one another. Color processes of this type are described in Land U.S. Patents 2,559,643, issued July 10, 1951, and 2,698,798, issued Jan. 4, 1955; Land and Rogers Belgian Patents 554,933 and 554,934, granted Aug. 12, 1957; International Polaroid Belgian Patents 554,212, granted July 16, 1957, and 554,935, granted Aug. 12, 1957; Yutzy U.S. Patent 2,756,142, granted July 24, 1956, and Whitmore and Mader U.S. Patent application Ser. No. 734,141, filed May 9, 1958.

The developing agents of the invention can, for instance, be employed in photographic dye developer image transfer systems, such as described in U.S. Patents 3,253,915Weyerts et al., issued May 31, 1966; U.S. Patent 2,559,643-Land, issued July 10, 1951; and U.S. Patent 2,698,798-Land, issued Jan. 4, 1955. In such systems, a dye diffusion transfer takes place. Compounds which contain in the same molecule, both the chromoporic system of a dye and a photographic silver developing moiety have been described as useful compounds in photographic elements for preparing color images by diffusion transfer processes. Such compounds are commonly called dye developers. Photographic elements containing such dye developers generally comprise a plurality of photosensitive silver halide emulsions wherein each of the emulsions is selectively sensitized to a different region of the spectrum. A dye developer is typically positioned contiguous to the silver halide in each of such emulsions. Such a photographic element can according to the invention contain a developer within the scope of the above structures in one of the layers of the element, such as in a gelatin overcoat layer. The photographic element after exposure can he processed with an alkaline composition with the latent image being developed in the image areas With the dye developers, this development immobilizing the dye developers in such image areas. The dye developers in the unexposed image areas diffuse to the surface imagewise and are transferred to a reception layer or receiving sheet to form a positive multicolor image. Similarly, such dye diffusion transfer systems can be used to prepare single color transfer prints.

The developers Within the scope of the invention can typically be employed as auxiliary developers in dye developer image transfer elements and processes.

They may also be used in emulsions intended for use in a monobath process such as described in Haist et al. U.S. Patent 2,875,048, issued Feb. 24, 1959, and in webtype processes, such as the one described in Tregillus et al. U.S. patent application Ser. No. 835,473, filed Aug. 24, 1939, now U.S. Patent No. 3,179,517.

Bridged 5,8 dihydro 1,2 dihydroxynaphthalenes or bridged 5,6,7,8 tetrahydro 1,2 dihydroxynaphthalenes, such as 5,8-methano-5,6,7,8-tetrahydro-1,2-dihydroxynaphthalene, within the scope of the above structures are suitable according to the invention as tanning developers. These compounds can 'be used as so-called external tanning developers, such as in aqueous developer solutions in which an exposed photographic emulsion is immersed until the desired density is achieved. They can also be used as so-called incorporated tanning developers, such as in colloid transfer processes and systems. An important advantage of these compounds compared to, for example, 4-phenyl catechol, is that they can be incorporated into or added to an emulsion, from an aqueous solution, and need not be added to an oil dispersion as is necessary with many developing agents, especially many other tanning developing agents. As incorporated tanning developers, they are especially suitable in coatings of the type described in U.S. Patent 2,596,756. For example, a coating of the type described in U.S. Patent 2,596,756 containing 5,8-methano-5,6,7,8-tetrahydro-1,2- dihydroxynaphthalene when activated with an alkali metal carbonate and urea solution and brought into contact with a receiving sheet according to U.S. Patent 2,596,756, produces a good colloid transfer.

The following examples are intended to illustrate our invention but not to limit it in any Way:

Example 1 A product is prepared having the following layers:

(1) Unhardened silver chlorobromide gelatin emulsion having a silver coverage of 260 mg. per square foot plus 3,6-dihydroxybenzonorbornane having a coverage of mg. per square foot, gelatin coverage of 1130 mg. per square foot.

(2) Unhardened gelatin 570 mg. per square foot-l-tartrazine.

(3) Stripping layer comprising gelatin and cellulose nitrate.

(4) Polyester support.

This material is exposed and processed as follows:

(1) Developed 60 seconds in aqueous 7 /2% Na CO /2% NaOH and 0.2% KBr.

(2) Stop bath 30 seconds in aqueous 5% Na SO (3) Stop bath 30 seconds in aqueous 5% acetic acid.

(4) Wash 5 minutes in water.

(5) Dry.

(6) Apply to damp copper cylinder and hold one to five minutes.

(7) Strip base from stripping layer.

(8)Wet with an equeous 2% borax solution containing sodium salicilate or sodium benzene sulfonate. 9) [Wash with Water to remove stripping layer and unhardened gelatin.

This coating strips easily, the Dmax is high, and has good development uniformity (no mottle).

Example 2 Example 1 is repeated except hydroquinone is used as a tanning developing agent in place of 3,6-dihydroxybenzonorbornane. When exposed and processed as in Example 1, this coating does not strip easily, and the Dmax is too low. This coating has poor development uniformity (high mottle).

Example 3 Example 1 is repeated except that 4-phenyl catechol is used as the tanning developing agent in place of 3,6-dihydroxybenzonorbornane. When exposed and processed as in Example 1, this coating does not tan at low density levels and therefore gives poor dot quality. This coating also has poor development uniformity (high mottle).

Example 4 Example 1 is repeated except that chlorohydroquinone is used as the tanning developing agent in place of 3,6-dihydroxybenzonorbornane. When exposposed and processed as in Example 1, this coating does not strip easily and the Dmax is too low. This coating also has poor development uniformity (high mottle).

Example 5 A fine grain unhardened chlorobromide emulsion is hand coated on a cellulose acetate film support at a coverage of mg. silver per square foot. The tanning developer to be tested is incoporated in the emulsion at a coverage of 0.13 mole per mole of Ag. The gelatin has a coverage of 236 g. of gelatin/ mole Ag. After exposing to a step wedge, samples are activated 30 seconds in a 5 percent solution of sodium carbonate and then sprayed for 30 seconds with 110 F. water. The unexposed areas are washed away in the 110 F. Water when employing 5,8-methano-5,6,7,8-tetrahydro 1,4 dihydroxynaphthalene; 5,8-ethano-5,8-dihydro 1,4 dihydroxynaph- 1 1 thalene; and 5,8-methano-5,8-dihydro 1,4 dihydroxynaphthalene of the formulas respectively:

OH OH OH The following compounds give unsa-tisfactorily low speed when present in an emulsion film coating activated in the same activator. They also give unsatisfactorily low speed when used in an activator having a higher pH than the 5 percent sodium carbonate solution.

Example 6 A photographic element as described in Example 1 is prepared except that the tanning developer is omitted from the silver halide emulsion. Instead, the tanning developer, 3,6-dihydroxybenzonorbornane, is incorporated in the developing solution in the amount of g. per liter. The remaining steps in the processing cycle are used as in Example 1. It is found that a similar satisfactory coating is obtained which strips easily at a high Dmax and good development uniformity.

Example 7 To 13.0 ml. of a silver chlorobromide emulsion is added 2.0 ml. of 10 percent saponin, g. of 10 percent gelatin, 213 mg. of 2-methyl-5,8-methano-5,S-dihydro-1,4-dihydroxynaphthalene dissolved in methanol, 1.2 ml. of sodium bisulfite solution (1 mg./ml. distilled water), and distilled water to 50 ml. (5.5 kg./mole Ag, 236 g. gelatin/mole Ag). The emulsion is coated on cellulose acetate film support at a coverage of about 190 mg. Ag/ft. Two strips of each coating are exposed, developed for 30 seconds in 5 percent aqueous sodium carbonate solution (68 F), and immersed in a stop bath. One strip is fixed in Kodak F-5 fixing bath, washed and dried for evaluation of development. The other strip is subjected for 30 seconds to a spray of water at 110 R; all of the emulsion is removed from the coating indicating no tanning by oxidized developer. 5,8-methano-5,6,7,S-tetrahydro 1,4-dihydroxynaphthalene, 5,8-ethano-5,8-dihydro- 1,4-dihydroxynaphthalene, and 5,8-methano-5,8-dihydro 1,4-dihydroxynaphthalene are coated and tested in an identical manner. The hot Water spray removed emulsion in the unexposed areas only, indicating tanning development.

Example 8 To 26 g. of 10 percent gelatin is added 2 ml. of 10 percent saponin, 4 ml. of sodium bisulfite solution (mg./ml.), and 680 mg. of 2-methyl-5,8-methano-5,8-dihydro-1,4- dihydroxynaphthalene dissolved in methanol, 0.8 ml. of 10 percent formaldehyde and distilled Water to 50 ml. The mixture is coated on cellulose acetate film support at a coverage of 500 mg. gelatin/ft), and dried. Over this coating is coated the emulsion containing the compound as described in Example 7 except that it also contains hardener. Two strips of each coating are exposed, developed for 30 seconds in 5 percent sodium carbonate solution (68 F.), immersed in a top bath, fixed in Kodak F5 fixing bath. One of the strips is washed and dried for evaluation of development. The other strip is bleached 5 minutes with a potassium ferricyanide bleach, rinsed, fixed in Kodak F-S fixing bath and washed. The coating is essentially free of stain. 5,8-methano-5,6,7,8-

tetrahydro-1,4-dihydroxynaphthalene, 5,8-ethano 5,8-

dihydro-1,4-dihydroxynaphthalene and 5,8-methano-5,8- dihydro-I,4-dihydroxynaphthalene are coated at equimolar levels in an identical manner and provide satisfactory results.

Example 9 To 13 ml. of a silver chlorobromide emulsion are added 2.0 ml. of 10 percent saponin, 15 g. of 10 percent gelatin, 230 mg. of Z-methyl-S,8-ethano-5,8-dihydro-1,4- dihydroxynaphthalene dissolved in 18.5 ml. methanol containing 0.25 ml. dimethylacetamide, and 1.2 ml. of sodium bisulfite solution (1 mg./ml. distilled water) (5.5 kg./mole Ag, 236 g. gelatin/mole Ag). The emulsion is coated on a cellulose acetate support at a coverage of about 190 mg. Ag/ft Two strips of each coating are exposed, developed for 5 seconds in an activator solution consisting of 54 g. of potassium hydroxide and 1.6 g. of potassium bromide in 800 ml. distilled water (68 F.), and immersed in a stop bath. One strip is fixed in Kodak F-5 fixing bath, Washed and dried for evaluation of development. The other strip is subjected for 30 seconds to a spray of water at F.; all of the emulsion is removed from the coating indicating no tanning by oxidized developer.

Example 10 A sample of 270 mg. of l,4,5,8-tetrahydro-1,4; 5,8- dimethanoanthracene-9,10-diol is coated, exposed and processed in the same manner as Example 9. All of the emulsion is removed from the coating by the spray of water at 110 F. indicating no tanning by oxidized developer.

Example 11 A mixture of 1.63 g. of 2-phenyl-5,8-mehano-5,8-dihydro-1,4-dihydroxynaphthalene and 30 ml. water is ball milled for 18 hours. From the 23.6 g. of foamy mixture recovered, 6.5 g. of clear water i decanted leaving 17.1 g. of mixture representing 1.2 g. of the compound. A 4.1 g. sample (286 mg. of compound) of the mixture is added to a mixture of 13 ml. of a chlorobromide emulsion, 2 ml. of 10 percent saponin, 15 g. of 10 percent gelatin and 1.2 ml. of sodium bisulfite solution (1 mg./ml. distilled water) and sufficient water is added to bring the mixture to 50 g. The mixture is coated, exposed and processed in the same manner as Example 9. All of the emulsion is removed from the coating by the spray of Water at 110 F. indicating no tanning by oxidized developer.

Example 12 A sample of 200 mg. of 5,8-methano-5,6,7,8-tetrahydro- 1,4-dihydroxynaphthalene is coated, exposed and processed in the same manner as Example 9. The emulsion is removed only in the non-exposed and very weakly exposed region of the coating by the stream of 110 F. water indicating good tanning in the more heavily exposed regions.

Example 13 A mixture of 1.24 g. of 5,8-ethano-5,6,7,8-tetrahydro- 1,4-dihydroxynaphthalene and 30 ml. of water is ball milled for 18 hours from which 24.1 g. of a foamy mixture is recovered, representing 955 mg. of compound. A 5.5 g. sample of the mixture (218 mg. of compound) is coated in the same manner as Example 11 and exposed and processed in the same manner as Example 9. The emulsion i removed only in the non-exposed and the very weakly exposed regions of the coating by the stream of 110 F. water indicating good tanning in the more heavily exposed regions.

Examples 9, 10 and 11 show non-tanning development occurring with 2-substituted bridged 1,4-dihydroxynaphthalenes and an anthracene-1,10-diol derivative While Examples 12 and 13 show tanning development with derivatives lacking such Z-substitution.

Example 14 A gelatin undercoat containing developing agent is prepared by mixing 26 g. of 10 percent gelatin, 2 ml. of 10 percent saponin, 735 mg. of Z-methyl-5,8-ethano-5,8-dihydro-1,4-dihydroxynaphthalene dissolved in 17 ml. methanol and 0.25 ml. dimethylacetamide, 4 ml. of sodium bisulfite solution (1 mg./ml. distilled water), and 0.8 ml. of 10 percent formaldehyde. The mixture is coated on cellulose acetate support at a coverage of 500 mg. gelatin/ft. and dried. Over this undercoat is coated the emulsion prepared like Example 9 except for having in addition 0.6 ml. of 10' percent formaldehyde. Two strips of the coating are exposed and processed for 5 seconds in the activator solution described in Example 9 (68 F.), placed in a stop bath, and then treated with Kodak F-5 fixing bath. One strip is washed and dried for evaluation of development, and the other is bleached for 5 minutes in a potassium ferricyanide bleach (68 F.), rinsed, treated with Kodak F-S fixing bath, washed and dried.

Example 15 A gelatin undercoat containing developing agent is prepared and coated exactly like that of Example 14 except for using 865 mg. of 1,4,5,8-tetrahydro-1,4,5,8-dimethanoanthracene-9,10-diol as the developer. On this is coated the emulsion prepared like Example 10 except for having in addition 0.6 ml. of 10 percent formaldehyde. Two strips of the coating are exposed and processed exactly like those of Example 14.

Example 16 A gelatin undercoat containing developing agent is prepared and coated exactly like that of Example 14 except that 12.9 g. of the ball milled mixture of Example 11, representing 910 mg. of 2-phenyl-5,8methano-5,8-dihydro-l,4-dihydronaphthalene is used as the developer and the undercoat mixture is taken to a total of 49' g. with Water. On top of this is coated the emulsion mixture prepared like Example 11 except for having in addition 0.6 ml. 10 percent formaldehyde. Two strips of the coating are exposed and processed exactly like those of Example 14.

Example 17 A gelatin undercoat containing developing agent is prepared and coated exactly like that of Example 14 except that 640 mg. of 5,8-methano-5,6,7,8-tetrahydro-1,4-dihydroxynaphthalene is used as the developer. On this is coated an emulsion mixture prepared exactly like that of Example 12 except that 125 mg. of the compound is used and 0.6 ml. of 10 percent formaldehyde is added. Two strips of the coating are exposed and processed exactly like those of Example 14.

Example 18 A gelatin undercoat containing developing agent is prepared and coated exactly like that of Example 14 except that 17.4 g. of the ball milled mixture of Example 13, representing 690 mg. of 5,8-methano-5,6,7,8-tetrahydro- 1,4-dihydroxynaphthalene is used as the developer and the 0 undercoat mixture is taken to a total of 49 g. with water. On top of this is coated the emulsion mixture prepared like Example 13 except for having in addition 0.6 ml. of

10 percent formaldehyde. Two strips of the coating are exposed and processed exactly like those of Example 14.

Example 19 Hydroquinone DHTMN .02M agent 15.9 min 8.3 min. .02M agent plus .002M 1-phenyl-3- 2.4 min 2.0 min.

pyrazolidone.

Example 20 For activator development tests a gelatin undercoat of the developer is coated on cellulose acetate film support at a coverage of 500 mg. gelatin/ft. and dried. On top of this, an emulsion layer containing the developer is coated at a coverage of about mg. Ag 1 ft. The undercoat mixture is prepared by adding about 17 ml. of the developer solution to a mixture of 26 g. of 10 percent gelatin, 2 ml. of 1 0 percent saponin and 4 ml. of sodium bisulfite solution (1 mg./ml.) and then adding 0.8 ml. of 10 percent formaldehyde. The emulsion mixture is prepared by adding 18.5 milliliters of the developer solution to a mixture of 13 ml. of a chlorobromide emulsion, 2 ml. of 10 percent saponin and 1.2 ml. of sodium bisulfite solution and then adding 15 ml. of 10 percent gelatin and 0.6 ml. of 10 percent formaldehyde. Strips of the coatings are exposed and developed at 68 F. in activator solutions A and B. Developers are given in Table I.

naphthalene-1,4-diol.

Crystallization of developer is encountered in coatings of Examples 1, 2 and 3. Activator processing results are given in Table II.

1 Relative speed.

For tanning tests the emulsion coat containing the developer is prepared as described above (except that the formaldehyde solution is omitted) and coated directly on cellulose acetate film support. Two strips of each coating are exposed, processed for 30 seconds in 5 percent aqueous sodium carbonate solution (68 F.), and immersed in stop bath. One strip is fixed in Kodak F-S fixing bath, washed and dried for evaluation of development. The other strip is subjected for 30 seconds to a spray of water at 110 F. All of the emulsions are removed from the coatings of compounds of Examples 3 and 7 but only emulsion in the unexposed areas is removed from coatings of compounds of Examples 1, 2, 5 and 6. The compound of Example 4 is not tested.

ACTIVATOR A 1 liter working solution 45% potassium hydroxide solution ml 150 Sodium bisulfite grams 40 Potassium bromide do 2 Sequestering agent do 1 Water to make 1 liter.

ACTIVATOR B Grams Phosphoric acid (86%) solution 4.49 Potassium hydroxide (45 solution 17.7 Potassium carbonate, anhydrous 22.5 Ethylenediamine tetra-acetic acid-Na; 1.5

Z-diethylaminoethanol 11.25 p-Toluenesulfonic acid, monohydrate 8.25 Tetraethylene glycol 15. Water to make 1 liter.

Example 21 When used as antifoggants, the following compounds are added to a medium-grained silver bromoiodide gelatin emulsion:

2 phenyl 5,8 ethano-5,8-dihydro-1,4-dihydroxynaphthalene:

S,8-methano-5,8-dihydro-1,4-dihydroxynaphthalene:

5,8 ethano 5,6,7,8 tetrahydro 1,4 dihydroxynaphthalene:

2 methyl 5,8 methano 5,8 dihydro-1,4-dihydroxynaphthalene:

2 phenyl 5,8 ethano 5,8 dihydro 1,4 dihydroxynaphthalene:

2 methyl 5,8 ethano 5,8 dihydro 1,4 dihydroxynaphthalene 5,8-ethano-5,8-dihydro-1,4-dihydroxynaphthalene:

The efficiency of the various antifoggants is determined by incubation of the emulsion after coating for one week at a temperature of 120 F. and at a relative humidity of 50 percent. The eificiency is determined by measuring speed, gamma, and fog of the incubated samples contalning an antifoggant and comparing these measurements with those of the same emulsion before incubation. Also, similar measurements are made on the same emulsion containing no antifoggant, before and after incubation. The exposures are made to an intensity scale test object on an Eastman Type 1b sensitometer and developed for 5 minutes at 68 F. in a developer of the following composition:

Water ml 500.0 p-Methylaminophenol g 2.5 Sodium sulfite g 30.0 Hydroquinone g 2.5 Sodium metaborate g 10.0 Potassium bromide g 0.5

Water to make 1.0 liter.

The tested samples are subsequently fixed, washed, and dried in the conventional manner as shown in the following results:

1 week Fresh test incubation gJmolo silver Rel. Rel. halide speed 7 Fog speed 7 Fog 100 1. 27 13 62 91. 47 6. 0 57 1. 38 .16 36 1. 20 24 6.0 83 1. 33 .10 76 1.10 .19 1. 2 69 1. 32 10 67 1. 12 18 1. 2 63 1.42 .10 67 1.10 .15 1.2 82 1.32 .11 71 1.05 .22 1. 2 60 1. 37 10 85 1. 12 .23 3.0 Results showed marked anti-logging 3.0 capacity of these compounds 1 7 Example 22 A negative photographic product, A, is prepared having the following layers:

Amount gelatin pe Component and amount in mg. per square square foot foot Layer number:

9 Gelatin 50.0 10

8 Blxefigigsitive silver bromoiodide 69 mg. of 49. 5

7 Yellow dye-developer: 1-phenyl-3-hexyl 48.0

carboxamide-4-p-(fi-hydroquinonyl ethyl)phenylazo-5-hydroxy pyrezole 48 mg./ft.

6 Gelatin 127. o

5 Green sensitive silver bromoiodide 103 mg. 43. 0

of Ag/itfl.

4 Magenta dye-developerz 4-1'sopropoxy-2- 92. 5

[p-(fl-hydroquinonylethyl)-phenylazo]-1- fia phthol 64 mg./it. and CaClz 18 mg./

3 Sodium alginate 27 mgJft. 0.0 20

2 Rail /s;n sitive silver bromoiodide 219 mg. of 86. 0

1 Cyan dye-developer: 5,8-bis-(B-hydro- 221.0

quinonyl-a-methyl)ethylamino quinizarin 146 mg./ft. support.

A second photographic product, B, is prepared the same as A with the exception that 8 milligrams per square foot of a developing agent, 4-methylphenyl hydroquinone is added to layer 9.

A third photographic product, C, is prepared the same as A with the exception that an amount, equimolar to that of the developing agent employed in B, of 2-phenyl-5,8- methano-5,-8-dihydro-1,4-dihydroxynaphthalene, is added to layer 9.

Each of the photographic products, A, B and C, are exposed in the same way imagewise to light. Each is thereafter identically processed by applying an alkaline activator solution to the emulsion surface and superimposing identical receiver sheets thereover.

The receiver sheets are composed of a white pigmented cellulose acetate support having a dye developer receiving layer containing a mixture of gelatin at a coverage of 300 mg. per square foot and 1-phenyl-S-mercaptotetrazole at a coverage of 15 milligrams per square foot.

The receiver sheets and the products A, B and C are permitted to remain in contact for one minute at 21 C. and then stripped apart.

The alkaline activator solution which is applied has the following composition:

The results are set out in the following table:

Patent 2,698,798, Land, produces unexpected lower minimum density, and increased relative speed in the green and blue sensitive layers.

Example 23 A multilayer color photographic element is prepared by coating the following layers on a cellulose acetate support employing the color formers and silver halide emulsions set out in US. Patent 3,046,129:

136.8 rug/ft. of 5,8-methano-5,8-dihydro-1,4-dihydroxynaphthalene are incorporated in layer 1 and 236.6 mg./ft. of this compound are incorporated in layer 11.

The element is exposed imagewise and processed to a color negative by (a) immersing the element for several seconds in a bath having the following composition:

Component LII-P 1-phenyl-3-pyrazolidone g 1 Sodium carbonate g Sodium hydroxide g 4 2-aminoe'thanol ml 25 S-methyl benzotriazole (1% aqueous solution) ml 25 Potassium bromide g 2 Distilled water to make 1 liter. pH--12.0

(b) fixing and washing out residual silver halide, (c)

rehalogenizing the resulting negative silver image, (d) color developing the rehalogenized silver, (e) bleaching, fixing, washing and drying employing the solutions and processing steps set out in US. Patent 3,046,129. This 50 produces a developed color image.

Example 24 The procedure set out in Example 23 is repeated with the exception that 79.2 mg./ft. of 5,8-methano-5,8-dihydro-1,4-dihydroxynaphthalene are incorporated in layer 1, 92.3 mg./ft. of this compound are incorporated in layer 4 and 140.2 mg./ft. of this compound are incorporated in layer 7.

Upon processing in the same manner as set out in Example 23, a good color image is produced.

Relative speed taken Dmax. Dmin, at a density of 0.8

Auxiliary developer and product Red Green Blue Red Green Blue Red Green Blue A, none 1. 55 1. 74 1. 26 48 51 100 100 B 4-methyl phenyl hydroquinone. 1. 63 1. 76 1. 74 17 24 27 58 118 112 C, bridged naphthohydroquinone compound. 1. 59 1. 73 1. 69 19 21 18 74 138 The results of this example demonstrate that the use Example 25 of the above bridged dihydroxynaphthalene compounds when employed in an emulsion layer of a photographic element for a so-called dye-developer transfer process, like that set out in, for example, US. Patent 2,559,643,

Land; US. Patent 3,253,915, Weyerts et al., and U8. 75

A single red-sensitive layer of silver bromoiodide emulsion is prepared and coated on a cellulose acetate support as set out in US. Patent 3,046,129. 104 mg./ft. of 5,8- methano 5,6,7,8 tetrahydro 1,4,7,9 tetrahydroxynaphthalene, also known as exo-anti-1,2,3,4-tetrahydro- 19 1,4-methanonaphthalene-2,5,8,9-tetrol and represented by the formula on l noon 45% KOH ml 150 NaHS g KBr g 2 Distilled water to 1 liter.

(b) immersing the element in a rinse bath, (c) color developing residual silver halide and (d) washing and drying employing the solutions and processing steps set out in US. Patent 3,046,129. This produces a developed image.

Example 26 The procedure set out in Example 25 is repeated with the exception that 94 mg./ft. of 2-methyl-5,8-methano- 5,8-dihydro-l,4-dihydroxybenzene is incorporated in the red-sensitive silver bromoiodide emulsion before coating on the support. Upon processing as in Example 25, a developed image is produced.

Example 27 The procedure set out in Example 25 is repeated with the exception that 88 mg./ft. of 5,8-methano-5,6,7,8- tetrahydro-l,4-dihydroxynaphthalene is incorporated in the red-sensitive silver bromoiodide emulsion before coating on the support. Upon processing, as in Example 25 a developed image is produced.

Bridged 5,6,7,8-tetrahydro-1,2 dihydroxynaphthalenes can be prepared b the following steps respectively, which refer to the preparation of 4-phenyl-5,8-methano 5,6,7,8- tetrahydro-l,Z-dihydroxynaphthalene, but are not limited thereto:

(A) silver oxide oxidation reaction of 4-phenyl pyrocatechol with cyclopentadiene (J. of Org. Chem, 30, 1655 (1965)) to produce:

This o-quinone aduct can also be prepared by oxidation with potassium ferricyanide buffered with sodium acetate in an aqueous acetone system. [Angew. Chem. 72, 581

(B) reaction of the product of (A) wtih acetic anhydride in pyridine to produce the corresponding diacetate:

03GB; open,

(C) hydrogenation in the presence of a palladium catalyst of the diacetate of (B) to produce:

(D) conversion of the product of (C) to the desired 4- phenyl-S,8-methano-5,6,7,8-tetrahydro 1,2-dihydroxynaphthalene by reaction with an inorganic acid in the presence of methanol.

Example 28 This example employs 4-methyl-5,8-methano-5,6,7,8- tetrahydro-1,2-dihydroxynaphthalene as an incorporated developer in a silver halide emulsion and in an overcoat over the emulsion.

A gelatin layer containing 4-methyl-5,8-methano-5,6,7, S-tetrahydro-1,2-dihydroxynaphthalene is coated as a cellulose acetate support at the rate of 0.7 millimoles of developer per square foot and 500 milligrams of gelatin per square foot. A fine grain silver bromoiodide photographic emulsion is coated over this layer at the rate of 190 mg. Ag/ftF, 415 mg. of gelatin/ft. and 0.224 millimoles of 4-methyl-5,S-methano-S,6,7,8-tetrahydro-l,2- dihydroxynaphthalene. The ratio of the bridged 1,2-dihydroxynaphthalene compound to silver is 0.53 mole of developer per mole of silver.

Strips of the resulting photographic element are exposed imagewise and processed for 5 seconds at 21 C. in an activator solution having the following composition:

Potassium hydroxide (45% solution) ml Sodium sulfite g 40 Potassium bromide g 2 Distilled water, 1 liter.

The strips are then immersed in an acetic acid stop bath for a few seconds, fixed and washed with water.

This results in a desired developed image. Processing in the activator solution for a longer period produces higher relative speed and gamma.

Example 29 Example 30 This example employs 5,S-methano-5,6,7,8-tetrahydro- 1,2-dihydroxynaphthalene in an aqueous alkaline developer solution for developing a latent image in a silver halide photographic emulsion.

An aqueous developer solution containing 0.4% by weight of 5,8-methano-5,6,7,S-tetrahydro-1,2-dihydroxynaphthalene and 4% by weight sodium carbonate is prepared by admixing the sodium carbonate and bridged-1,2- dihydroxynaphthalene into the appropriate amount of water.

An exposed fine grain silver chloride photographic emulsion is treated with this solution at 20 C. Maximum den4sity after 20 seconds is 2.02 and after 40 seconds is 2.5

It will also be appreciated that when the developers of this invention are used in an aqueous alkaline solution, that the amounts used may be varied widely depending upon the emulsion used, whether the emulsion contains 21 a developing agent, the result desired, the other components in the developing solution such as one or more other developers in admixture, etc.

The supports which may be used for the silver halide emulsions referred to herein include those customarily used, such as paper, glass, metal, wood, cloth, polymeric materials such as polyolefins, polyesters, cellulose esters, polyamides, polystyrene, polycarbonates, etc. A particularly useful support is paper coated with a polyolefin such as polyethylene.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described herein and as defined in the appended claims.

We claim:

1. A photographic silver halide element comprising a support having a layer containing a compound of the class consisting of bridged dihydro-1,4-dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-1,Z-dihydroxynaphthalenes, bridged tetrahydro-1,Z-dihydroxynaphthalenes, bridged tetrahydro- 9,IO-dihydroxyanthracenes, bridged heXahydro-9,10-dihydroxyanthracenes, and bridged octahydro-'9,l0-dihydroxyanthracenes.

2. A photographic element as in claim 1 wherein said compound is contained in a photographic silver halide emulsion layer on said support.

3. A photographic element as in claim 1 wherein said compound is contained in a hydrophilic colloid layer contiguous to a photographic silver halide emulsion layer on said support.

4. A photographic element as in claim 1 comprising a support having a photographic silver halide emulsion layer containing an antifoggant concentration of a compound of the class consisting of bridged dihydro-l,4-dihydroxynaphthalenes, bridged tetrahydro 1,4 dihydroxynaphthalenes, bridged dihydro-l,2-dihydroxynaphthalenes, bridged tetrahydro-1,2-dihydroxynaphthalenes, bridged tetrahydro-9,IO-dihydroxyanthracenes, bridged hexahydro- 9,lO-dihydroxyanthracenes, and bridged octahydro-9,10- dihydroxyanthracenes.

5. A photographic element as in claim 1 wherein said colloid layer contains at least one of (a) 5,8-methano or 5,8-ethano-5, 8-dihydro-1,4-dihydroxynaphthalene;

(b) -5,8-methano or 5,8-ethano-5,6,7,8-tetrahydro-1,4-

dihydroxynaphthalene;

(c) 5,8-meth-ano or 5,-8-ethano-5,8-dihydro-1,2-dihydroxynaphthalene; or

d) 5,8-methano or 5,8-ethano-5,6,7,8-tetrahydro-1,2-

dihydroxynaphthalene.

6. A photographic element as in claim 1 wherein said colloid layer contains at least one of 1,4,*5,8-tetrahydro- 1,4; 5,8-dimethano or 1,4; 5,8-diethanoanthracene-9,10- diol,

7. A photographic element as in claim 1 wherein said layer is unhardened light sensitive silver halide gelatin emulsion and said compound is an unsubstituted bridged 5,8-dihydro-l,2 or 1,4-dihydroxynaphthalene.

8. A photographic element as in claim 1 containing at least one layer containing a color coupler compound.

9. A photographic element as in claim 1 comprising a support having thereon at least one photographic layer sensitive to the blue region of the spectrum, at least one photographic layer sensitive to the green region of the spectrum and at least one photographic layer sensitive to the blue region of the spectrum, containing in at least one layer of said element a compound of the class consisting of bridged dihydro-l,4-dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro- 1,Z-dihydroxynaphthalenes, bridged tetrahydro-1,2-dihydroxynaphthalenes, bridged tetrahydro 9,10 dihydroxyanthracenes, bridged hexahydro-9,IO-dihydroxyanthracenes, and bridged octahydro-9,IO-dihydroxyanthracenes.

10. A multilayer photographic element as in claim 9 wherein at least one layer contains a dye-developer.

11. A multilayer photographic element as in claim 9 wherein at least one layer contains a dye-developer and at least one layer contains 2-phenyl-5,8-methano-5,6,7, 8- tetrahydro-1,4-dihydroxynaphthalene.

12. A photographic silver halide emulsion containing a compound of the class consisting of bridged dihydro- 1,4-dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-l,Z-dihydroxynaphthalenes, bridged tetrahydro-1,2-dihydroxynaphthalenes, bridged tetrahydro 9,10 dihydroxyanthracenes, and bridged hexahydro 9,10 dihydroxyanthracenes, and bridged octahydro-9,IO-dihydroxyanthracenes.

13. A photographic silver halide emulsion as in claim 12 wherein said emulsion is unhardened and said compound is a tanning silver halide developing agent.

14. A photographic silver halide developer composition comprising an alkaline development activator, a compound of the class consisting of bridged dihydro-1,4-dihydroxynaphthalenes, bridged tetrahydro 1,4 dihydroxynaphthalenes, bridged dihydro-l,Z-dihydroxynaphthalenes, bridged tetrahydro-l,Z-dihydroxynaphthalenes, bridged tetrahydro-9,IO-dihydroxyanthracenes, bridged octahydro- 9,10-hydroxyanthracenes, bridged heXahydro-9,l0-dihydroxyanthracenes and an auxiilary silver halide developing agent.

15. A composition as in claim 14 comprising an aqueous alkaline silver halide developer solution.

16. A composition as in claim 14 comprising a solid silver halide developer composition.

17. A composition as in claim 14 wherein said compound is 5,8-methano or 5,8-ethano-5,8-dihydro-1,2 or 1,4-dihydroxynaphthalene.

18. A composition as in claim 14 wherein said compound is 5,8-methano or 5,8-ethano-5,6,7,8-tetrahydro- 1,2- or 1,4-dihydroxynaphthalene.

19. A composition as in claim 14 wherein said compound is 2-l0wer alkyl or 2-phenyl, 5,8-meth'ano or 5,8- ethano-5,8-dihydro-1,4-dihydroxynaphthalene. thalene.

20. A composition as in claim 14 wherein said compound is 1,4,5,8-tetrahydro-1,4; 5,8-dimethanoanthracene- 9,10-dio1.

21. A process for developing a latent image in an exposed photographic silver halide emulsion comprising contacting said emulsion with an aqueous alkaline solution containing a compound of the class consisting of bridged dihydro-1,4-dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-1,2- dihydroxynaphthalenes, bridged tetrahydro-l,Z-dihydroxynaphthalenes, bridged tetrahydro-9,10 dihydroxyanthracenes, bridged hexahydro-9,IO-dihydroxyanthracenes, and bridged octahydro-9,10-dihydroxyanthracenes.

22. A process for developing a latent image in an exposed photographic silver halide emulsion containing a compound of the class consisting of bridged dihydro-1,4- dihydroxynaphthalenes, bridged tetrahydro-1,4-dihydroxynaphthalenes, bridged dihydro-1,Z-dihydroxynaphthalenes, bridged tetrahydro-1,Z-dihydroxynaphthalenes, bridged tetrahydro 9,10 dihydroxyanthracenes, bridged hexahydro-9,I-O-dihydroxyanthracenes, and bridged octahydro- 9,10-dihydroxyanthnacenes, comprising imbibing into said emulsion an alkaline activator.

References Cited UNITED STATES PATENTS 2,886,577 5/1959 Yun Fan 260-396 3,287,129 11/1966 Rees et al. 96-66 3,158,482 11/1964 Lucas 96-662 3,345,170 10/1967 Evans et al 96-66 (Other references on following page) 23 24 FOREIGN PATENTS NORMAN G. TORCHIN, Primary Examiner 642,449 5/ 964 Belgi m- CAROLYN DAVIS, Assistant Examiner OTHER REFERENCES U.S. Cl. X.R. M e C.E.N. Th Theo of the Photo ra hic Process, 1954,e 548451? Ty g p 5 96--66, 69, 73, 76, 95, 100, 109

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 32 59,5 1) Dated August 5, 1969 Inventor(s) Clarence E. McBride, David F. O'Brien, John W. Gates, Jr

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[- In column 1 line 30 (page 1 line 3 of Examiner s j Amendment), "polyhydroxynaphthalenes" should be --dihydroxynaphthalenes-- In column 3, line 73 (page 5, line 23 of the application), please delete the second occurrence of "R K, a d insert In column 14,, line 1 6 (page 6, line 1 of the application), "1 ,l -dihydroxynaphthalenes" should be --1 ,Z-dihydroxynaphthalenes--; in column 14, line 66 (page 7, line 1 1 of the application) "5,8-methano-5, 6,7,8-"dih"yd1"0" 'shou'ldr'ea'd 5 ,8-ethano- 5,6',7,8-tetrahydro In column 5, line 75 (page 9, line 22 of the application), "5.8-methano" should be --5,8-methano--.

In column 6, line 28 (page 1 0, line 15 of the application) "meulsion" should be --emulsion--; in column 6, line 37 (page 10, line 23 of the application), "continuents" should be --oonstituents--; in column 6, line 614. (page 11 line 18 of the application), please delete the second occurrence of "both".

In column 7, line 5 (page 12, line 5 of the ap lication), "compounds" should be --compound--; in column 7, line 14.6 (page 13, line 1 3 of the application) "puhotographic" should be --photographic.

In column 9, line 52 (page 18, line 15 of the application), "Aug. 214., 1 939" should be --Aug. 214., 1 959--.

In column 1 0, line 31 (page 20, line 2 of the ap lication) "aqueous" should be --aqueous--; in column 1 0, line 55 (page 20, line 214. of the application) "exposposed" should be --exposed-- In column 12, line 314 (page 214, line 13 of the application), "mehano" should be --methano--.

In column 13, line 36 (page 26, line 21 of the application), "1 ,14.-dihydronaphthalene" should be --1 ,14.-dihydroxynaphthalene--.

In column 1%, line 28 (page 28, line 11 of the application), "190 mg. Ag 1 ft should be "190 mg. Ag/ft In column 18, line 1 9 (page 36, line 7 of the application) "gelatine" should be --gelatin--.

(continued on page 2) PAGE 2 "H050 UNITED STATES PATENT OFFICE 5/ 5g) CERTIFICATE OF CORRECTION Patent No. 3,LL59,5)+9 Dated August 5, 1969 Inventor(s) Clarence E. McBride, David F. O'Brien, John W. gates,

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r In column 19, line 62 (page 38, line 23 of the application), "aduct" should be --adduct--.

In column 22, claim 114., line 28, (page 2, claim 12, last line of amendment dated B/1L ./68) "auxiilary" should be --auxiliary--; in column 22, claim 19, line 14.3 (claim 18 in the application), please delete "thalene".

SIGNED MID SEALER SEP 291970 Ana: 1

Edw g? M, FIGChd. Ira I. W, m. Amstmg Officer commission or rated-B 

